Skynet-5D: Military satellite's classified tech
19 December 2012 Last updated at 02:02 GMT
A powerful new telecommunications satellite is being launched on Wednesday for the British military.
The Skynet-5D spacecraft is the final piece in a multi-billion-pound system that enables UK forces to stay connected wherever they are deployed in the world.
Because it is a military system, Skynet has been designed to evade enemy jamming and eavesdropping, and as such contains a number of classified technologies.
BBC science correspondent Jonathan Amos was granted special access to the spacecraft before its launch.